Some design and prototyping issues on a 20000 rpm HDD spindle motor with a ferro-fluid bearing system

A high-speed ferro-fluid bearing spindle motor for hard disk drive is introduced. Some design challenges and considerations on electrical motor, bearing system and spindle structure are addressed. The testing results of the prototypes are presented and discussed. The shown testing results of the prototypes indicate that the objective of developing a high-speed, high-performance, fluid-bearing spindle motor is fulfilled. It is a prospective spindle motor to be used in future hard disk drives.